Investigation Survey Design and Construction of 20 Nos of Nature based Sewage Treatment Plants NSTPs under Package-II with Cumulative Capacity of 3.013 MLD at various ULBs in the State of Andhra Pradesh based on Modern Technology with three months trial run Post Completion, Operation Maintenance of entire Sewage Treatment Plant for 05 (five) years including 02 two years Defect Liability Period EPC Tender